(1) Field of the Invention
The present invention relates to a drum type drying/washing machine which is able to singly perform washing through drying laundry, and which holds the laundry in a drum which is driven to rotate about a horizontal shaft and which dries it by cooling-dehumidication using cooling water while performing dehydration by a high speed rotation of the drum.
Further, the present invention relates to a drum type drying/washing machine that performs washing and dehydrating (and optionally drying) fabrics such as clothes etc., as well as a machine that only performs a drying operation.
(2) Description of the Prior Art
In conventional drum type driers, for example, drum type full automatic drying/washing machines, a method called `cooling-dehumidication` has been known in which drying is performed by using air ventilation, heating and water cooling as soon as the drying operation is started. There has not been any known method in which drying is performed by stopping the flow of cooling water for a predetermined period of time immediately after the drying is started, in which dehydration by high speed drum rotation will be performed during drying, or in which clothes are relocated during drying by performing a high speed drum rotation.
There is a method which can reduce the power consumption of the heater near the end of the drying process, but no method has been found which stops and starts the flowing of cooling water at intervals whilst reducing the power consumption of the heater.
Accordingly, in the conventional drum type driers of this kind, much water and time were needed for drying and still there was a problem that drying unevenness would occur depending on the locations of clothes.
In the drum type drying/washing machine, detergent and water are supplied after laundry has been loaded to the loading port for laundry. Then, after washing, the washing liquid is drained and dehydrated. Subsequently, the laundry is supplied with water, rinsed and dehydrated. At the final stage, the laundry undergoes the heat drying treatment using a heater.
High-temperature, low-humidity air which is obtained by the heat treatment using the heater is supplied into the drum through an orifice located above the loading port of the drum type drying/washing machine so that, whilst the laundry is heated, damp contained in the laundry is removed to be exhausted from the drum. The exhausted air which now has become of high temperature and high humidity is transported through a duct around which cooling water is supplied from above the duct, so that the moisture in this air is condensed by the cooling water, and thus the air becomes of low temperature and low humidity. This air is further sucked out by a fan to the drying heater. The thus delivered air is heated to be of high temperature and low humidity, and then is blown into the drum through a blower port.
The above conventional drum type drying/washing machine, however, needed a long running time. Specifically, for drying/washing a 2 kg laundry, it took 162 min. in total, 72 min. for washing and 90 min. for drying. For a 3 kg laundry, it took 222 min. in total, 80 min. for washing and 142 min. for drying.
Japanese Patent Application Laid-Open Sho 61 No.234897 has proposed an idea in which the dehydration rate is increased by taking in hot air which is discharged from a clothing drier into the dehydrating container of a two-tub washing machine. However, this proposal is not practical.
Further, in accordance with conventional drum type washing machines, the drum is made to turn at such a low speed that materials to be processed are able to move during washing, whereas dehydration is performed by rotating the drum at such a high speed that the materials to be processed are stuck to the interior peripheral wall surface of the drum. However, such control suffers from a problem that if the materials to be processed are distributed unevenly inside the drum, anomaly vibrations might occur. Various methods have been proposed to solve this problem.
For example, Japanese Patent Publication Sho 49 No.9506 has proposed a drum type washing machine including a detector which detects the horizontal vibrating amplitude of the drum, over a certain period of time longer than one-cycle (one revolution) of the drum when the drum is rotated at a low rate, and based on the detected result, only if the average of the detected values is not more than a predetermined value, the driving state of drum will be transferred to a high speed rotation mode.
Japanese Patent Publication Sho 50 No.16099 has proposed a drum type washing machine including a detector which detects the horizontal vibrating amplitude of the drum, so that this detector will detect the vibrating amplitude of the water tank containing the drum during the rotation at a low rate, and only if the magnitude of the vibrating amplitude is not more than a predetermined value and the state is continued over a certain period of time longer than one-cycle (one revolution) of the drum, the driving state of the drum is transferred to a high speed rotation mode.
Japanese Patent Application Laid-Open Hei 3 No.86197 has proposed a drum type washing machine wherein the drum is rotated for pre-dehydration at a rate in between that of the low speed turn for washing and the high speed rotation for dehydrating, and only if the variation of the detected value outputted from a rotational speed detector which detects the rotational speed of the drum is not more than a previously selected value, the driving state of the drum is transferred to a high speed rotation mode.
It is true that all the above conventional configurations have some effect at drastically reducing the occurrence of anomaly vibrations, but they are still not able to ensure the prevention of anomaly vibrations at every case. Specifically, in the former two configurations, the materials to be processed would roll over in the drum during the low speed turn. Therefore, the drum could not become stabilized but would constantly change in its vibrating amplitude even within one revolution. Accordingly, if the driving state of the drum is transferred to the high speed rotation mode while the mean value of the vibrating amplitude is not more than a predetermined value, there is no assurance that the drum will be set into the high speed rotation mode whilst maintaining an even distribution. Although these configurations lent themselves to suppress significantly abnormal vibrations to a certain level, the effect was not sufficient to further eliminate lower level vibrations.
On the other hand, in the latter configuration, the materials to be processed would roll over during the pre-dehydrating rotating whilst sticking to and peeling off the inner peripheral wall of the drum. That is, the materials to be processed, most of the time, would not be stuck permanently to the inner peripheral wall of the drum. Since the variation of unbalance is detected approximately each revolution at this rotational rate, it will be delayed about one revolution behind when the driving state of the drum is transferred to the high speed rotation mode. During this time, if the materials to be processed roll over, the driving state of the drum may not always transfer to a high speed rotation mode keeping the operation of the drum normal.
Thus, in the conventional configuration, since the vibration of the drum was detected at a rotational speed when the materials to be processed in the drum were constantly rolling over, when the vibration of the drum was detected to be low, it was not certain whether the driving state of the drum could be transferred into the high speed rotation mode whilst the drum was kept at that state. That is, there was a time lag or delay between the time when it was judged whether the drum could be transferred to the high speed rotation mode and the time when the drum was actually transferred to the high speed rotation mode. During this span of time, the state of the materials to be processed might have changed, so that it was impossible to transfer the driving state of the drum to the high speed rotation mode whilst the vibration was being maintained lower than a designated level.
The above problems are not limited to the scope of the drum type washing machines, but drum type driers dedicated only to drying as well as other drum type rotary processing apparatuses have suffered from similar problems.